at the moment I have some wierd issues with my Logitech 5.1 speakers (some x-540 I think it is) alone with my Sound Blaster Audigy (maybe SE).
when connecting in 2.1 mode and testing, left front&right play as they should, so does right back, but right front and subwoofer seems to be swapped.
and when connecting in 5.1 it seems to be the same... my subwoofer says Right front...
and actually when connecting in 2.1 the sides seems to be switched... but thats just fixed through swapping the audio connections at the little connector (3port mini-jacks and 2port audio)
oh well, gonna try reinstalling software and see what happens